I had a fully functioning ubuntu 14.04 serving up via nginx a passenger/ror site with 'some' php.

The passenger/ror bit works fine after the upgrade however any attempt at accessing my php files gives a 404 Not Found error:

The error.log for nginx shows the following:

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2017/04/22 11:16:22 [crit] 16531#0: *1 connect() to unix:/var/run/php/php7.0-fpm.sock failed (13: Permission denied) while connecting to upstream, client: 212.159.100.115, server: resys.gourmindia.com, request: "GET /phpinfo.php HTTP/1.1", upstream: "fastcgi://unix:/var/run/php/php7.0-fpm.sock:", host: "resys.gourmindia.com"

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My question is what should the /var/run/php/php7.0-fpm.sock have as permission?

ALL help gratefully received with thanks.

Purvez